Derivatives and Hedging Activities (Details 2) (Not Designated as Hedging Instrument [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Gains and losses recognized in income on non-designated hedging instruments
Gains and losses recognized in income on derivatives	$ 598	$ (2,567)
Mortgage loan commitments [Member] | Other income [Member]
Gains and losses recognized in income on non-designated hedging instruments
Gains and losses recognized in income on derivatives	(1,691)	48
Forward sales contracts [Member] | Other income [Member]
Gains and losses recognized in income on non-designated hedging instruments
Gains and losses recognized in income on derivatives	2,244	(2,275)
Foreign exchange contract [Member] | Other income [Member]
Gains and losses recognized in income on non-designated hedging instruments
Gains and losses recognized in income on derivatives	45	0
Other [Member] | Other Expenses [Member]
Gains and losses recognized in income on non-designated hedging instruments
Gains and losses recognized in income on derivatives	$ 0	$ (340)